In recent years it has become feasible to manufacture diamond films of sufficient thickness to permit the manufacture of a diamond film wafer for use as a base material for electronic circuits, either as a direct electrical substrate for devices or as a circuit board on which circuit devices or chips such as VLSI (very large scale integrated) circuits are mounted. Primarily two characteristics of diamond material make it especially suited for such purposes. While on the one hand, it is an excellent electrical insulator, at the same time it is also a superb heat conductor, with a heat conductivity about 5 times that of copper.
The presently available methods of forming diamond wafers by deposition from a plasma, however, typically result in a structure which may be flat on one face as a result of being deposited on a flat and smooth deposition substrate, but nevertheless will have an uneven and rough opposite face on the side where deposition took place. Such unevenness is a serious problem for any semiconductor manufacturing applications, which generally involve at least one photolithography step requiring the substrate to have substantially parallel and flat opposing faces, the required degree of parallelism depending upon the depth of field of the photolithographic equipment used. Smoothing the uneven face of a diamond film wafer is a costly finishing process involving grinding with diamond abrasive.